From the New York Times best-selling author of the Emily Windsnap series comes a captivating adventure about family, friendship, and the bonds that bridge time. In a sleepy seaside village, Mia's grandad has vanished, and Mia's new friend, Dee, leaves notes, but never manages to meet Mia in person. Will Mia be able to solve the mystery of where--and when--her grandfather and friend might be before time and tide forever wash away their futures?